In instances in which a spiked tubular outlet associated with a tap has entered a flexible packaging bag as indicated above, applicant considers it to be desirable to lock the flexible packaging bag material onto the outer surface of the tubular outlet member. To this end, there has been proposed a clamping sleeve that cooperates with a slightly enlarged region of the outer surface of the outlet member so that a doubled over ring of the plastics material of the packaging bag is clamped firmly onto the outer surface of the outlet member.
For this purpose, there is proposed, in international patent publication no WO 03/070593, manually engagable co-operating formations on a tap and tubular outlet unit on the one hand and a clamping sleeve on the other. These formations are typically of a bayonet and socket type of construction so that manual manipulation of the sleeve relative to the tap and tubular outlet unit causes axial movement of the sleeve on the tubular outlet and consequent clamping of the plastic material.
Whilst the latter operates effectively in use, there is always the danger that a user will fail to engage the sleeve correctly, will even fail to take steps to engage it at all, and that could, in turn, result in the clamping being ineffective. Also, in the common instance that the sleeve carries a mounting flange arrangement, the tap could be loose relative to the mounting flange if the formations become, or remain, disengaged.
It is to be understood that the term liquid as used in this specification is intended to include semi-liquids such as those that may flow rather slowly or only with some encouragement as, for example, by a slightly elevated pressure being exerted on the outside of the flexible packaging bag. Typical of such semi-liquids are food condiments such as sauces, mayonnaise, concentrated fruit and vegetable juices, high viscosity oils, etc.